Poly-substituted phthalocyantines

ABSTRACT

The use of substituted phthalocyanines for the generation of singlet oxygen in which at least one of the peripheral carbon atoms in the 1-16 positions of the phthalocyanine nucleus (M k  Pc) of Formula (1): ##STR1## wherein: M is selected from H, metal, halometal, oxymetal and hydroxymetal; and 
     k is the inverse of 1/2 of the valency of M; is linked via an oxygen atom to an aromatic radical and the remaining peripheral carbon atoms are unsubstituted or substituted by any combination of atoms or groups and sulphonated derivatives thereof provided that the phthalocyanine absorbs electromagnetic radiation at a wavelength from 650 nm to 800 nm.

This is a division of application Ser. No. 08/344,682, filed Nov. 17,1994, now U.S. Pat. No. 5,486,274 which is a Rule 62 File WrapperContinuation Applicaition of application Ser. No. 07/777,719, filed Oct.21, 1991, abandoned.

This invention relates to the use of certain poly-substitutedphthalocyanine compounds and certain sulphonated derivatives thereof togenerate singlet oxygen, to the methods of preparing such compounds andto certain novel substituted phthalocyanines.

The present invention relates to the use of substituted phthalocyaninesfor the generation of singlet oxygen, in which at least one of theperipheral carbon atoms in the 1-16 positions of the phthalocyaninenucleus (M_(k) Pc), as shown in Formula (1): ##STR2## wherein: M isselected from H, metal, halometal, oxymetal and hydroxymetal; and

k is the inverse of 1/2 of the valency of M; is linked via an oxygenatom to an organic radical, hereinafter referred to as pendant organicradical, the remaining peripheral carbon atoms being unsubstituted orsubstituted by any combination of atoms or groups and sulphonatedderivatives thereof provided that the phthalocyanine absorbselectromagnetic radiation at a wavelength from 650 nm to 800 nm.

In the present phthalocyanines the phthalocyanine nucleus may be metalfree or it may be complexed with a metal, an oxymetal group, a hydroxymetal group or a halometal group represented by M i.e. it may carry twohydrogen atoms at the centre of the nucleus or it may carry one or twometal atoms or oxymetal groups or hydroxy metal groups or halometalgroups complexed within the centre of the nucleus. Preferred metalsrepresented by M are those of Groups IA, IIA, IIIB, IVB, 1st, 2nd and3rd transition rows and the lanthanide series of the Periodic Table.

Examples of suitable metals, halometal groups, hydroxy metal groups andoxymetal groups represented by M are Li, Na, K, Mg, ClAl, OHAl, Ca,ClSc, OHSc, Ni, Cu, Zn, ClGa, HOGa, OHRh, ClRh, ClIn, BrIn, OHIn, Sn,Ba, Ir, SiCl₂, SiO, Si(OH)₂, Pt, Pd, ClRu, OHRu, Cl₂ Ge, (OH)₂ Ge,P(V)Cl₃, P(III)Cl, POCl, R⁴ Al, R⁴ Sc, R⁴ Gr, R⁴ Ga, R⁴ OAl, R⁴ OSc, R⁴OCr, R⁴ OGa, R⁴ ORh, R⁴ Rh, R⁴ In, R⁴ OIn, R⁴ OSm, SiR⁴ ₂, Si(OR⁴ ₂), R⁴Ru, R⁴ ORu, R⁴ ₂ Ge, (R⁴ O)₂ Ge, P(V)OR⁴, P(III)OR⁴, POR⁴ and POOR⁴ inwhich R⁴ is straight or branched chain C₁₋₁₂ -alkyl, aryl or heteroaryl.

Where R⁴ is alkyl it is preferably C₁₋₆ -alkyl; where R⁴ is aryl it ispreferably selected from phenyl, benzyl, toluyl and 2-naphthyl and whereR⁴ is heteroaryl it is preferably pyridazyl or pyridyl.

In the present phthalocyanines it is preferred that M is Zn, ClAl, OHAl,ClRh, OHRh, ClIn, BrIn, OHIn, ClGa, OHGa, Pt, Pd, Li, Na, K, Ca, Ba, Mg,ClSc or OHSc, it is especially preferred that M is Zn, ClAl, OHAl, ClRh,OHRh, ClIn, BrIn, OHIn, ClGa, OHGa, Pt and Pd.

In the phthalocyanines used in the present invention each of the pendantorganic radicals linked via oxygen to the phthalocyanine nucleus isindependently selected from aromatic, heteroaromatic, aliphatic andalicyclic radicals, such that any one phthalocyanine nucleus may carrytwo or more different organic radicals.

It is preferred that each pendant organic radical is independentlyselected from mono- and bi-cyclic aromatic and heteroaromatic radicals.

Examples of suitable mono- and bi-cyclic aromatic and heteroaromaticradicals are phenyl, naphthyl, especially naphth-2-yl, pyridyl,thiophenyl, furanyl, quinolinyl, thiazolyl, benzothiazolyl and pyrimidyleach of which may be substituted.

Where the pendant organic radical is an aliphatic or alicyclic radicalit is preferred that it is selected from C₁₋₂₀ -alkyl especially C₁₋₁₀-alkyl; C₂₋₂₀ -alkenyl especially C₃₋₁₀ -alkenyl and C₄₋₈ -cycloalkylespecially cyclohexyl, each of which may be substituted.

Optional substituents for the pendant organic radicals are preferablyselected from C₁₋₂₀ -alkyl, especially C₁₋₄ -alkyl; C₁₋₂₀ -alkoxy,especially C₁₋₄ -alkoxy; C₁₋₂₀ -alkenyl, especially C₂₋₄ -alkenyl; C₁₋₂₀-alkylthio, especially C₁₋₄ -alkylthio; C₁₋₂₀ -alkoxycarbonyl,especially C₁₋₄ -alkoxycarbonyl; hydroxyC₁₋₄ -alkoxy; aryl, especiallyphenyl; C₁₋₄ -alkylaryl, especially benzyl; arylthio, especiallyphenylthio; halogen, especially fluoro, chloro and bromo; --CN; --NO₂ ;--CF₃ ; --COR², --COOR², --CONR² R³, --SO₂ R², --SO₂ NR² R³, --NR² R³and --OR² in which R² and R³ are independently selected from --H; alkyl,especially C₁₋₄ -alkyl; aryl, especially phenyl; C₁₋₄ -alkylaryl,especially benzyl and --SO₃ A in which A is H, or a metal or ammoniumion or substituted ammonium ion.

In the phthalocyanines used in the present invention it is preferredthat from 4 to 16 of the peripheral carbon atoms are linked via anoxygen atom to a pendant organic radical and it is especially preferredthat all 16 peripheral carbon atoms are linked via an oxygen atom to apendant organic radical.

Examples of suitable atoms or groups which can be attached to any of theremaining peripheral carbon atoms of the phthalocyanine nucleus arehydrogen, halogen, sulphonate groups --SO₃ A in which A is H, or a metalor ammonium ion or a substituted ammonium ion, and any of the pendantorganic radicals described above and hereinafter represented by R. It ispreferred that the atoms or groups attached to the remaining peripheralcarbon atoms are selected from --H, --F, --Cl, --Br, --I, --SO₃ H, --SO₃Na, --SO₃ K, --SO₃ Li, and --SO₃ NH₄ or any combination thereof. It isespecially preferred that these atoms or groups are --H, --Cl, --Br,--SO₃ H, --SO₃ Na or --SO₃ NH₄.

The sulphonated derivatives of the phthalocyanines used in the presentinvention carrying up to 50 SO₃ A groups, preferably up to 40 SO₃ Agroups and more preferably up to 30 SO₃ A groups, which are attacheddirectly to the phthalocyanine nucleus and/or to the pendant organicradicals are a preferred group of compounds for the present invention.

In the preferred group the average number of SO₃ A groups is preferablyfrom 2 to 40 and more preferably from 2 to 30 and especially preferably16 to 30. It is also preferred that for each pendant organic radicalthere is at least one SO₃ A group, although each organic radical maycarry none, one or more than one SO₃ A group.

Where A is a metal ion it is preferably an alkali or alkaline earthmetal ion, especially an alkali metal ion such as a sodium, potassium orlithium ion. Where A is an ammonium ion it is preferably ⁺ NH₄ or asubstituted ammonium ion which enhances the water-solubility of thecompound or a substituted ammonium ion of the formula ⁺ NQ₄ whichenhances the alcohol solubility of the compound. Examples of suitablesubstituted ammonium ions which enhance the water solubility of thecompound are mono, di, tri and tetra alkyl and hydroxyalkyl ammoniumions in which the alkyl groups preferably contain from 1 to 4 carbonatoms such as ⁺ N(CH₃)₄ ; ⁺ N(C₂ H₅)₄ ; ⁺ N(C₂ H₄ OH)₄ ; ⁺ NH₃ CH₃ ; ⁺NH₂ (CH₃)₂ and ⁺ NH(CH₃)₃.

In the substituted ammonium ion of the formula NQ₄ at least one Q is afatty aliphatic group and any remaining Q groups are C₁₋₄ -alkyl or H.The fatty aliphatic group represented by Q preferably contains from 4 to16, more preferably from 7 to 12 and especially preferably 7 to 9 carbonatoms. Preferred fatty aliphatic groups are alkyl and alkenyl groupswhich have straight- or branched-chains. Preferred alkyl groups,represented by Q, containing 8 or 9 carbon atoms are,3,5,5-trimethyl-hexyl, 1,1,3,3-tetramethylbutyl and 2-ethylhexyl.Examples of other aliphatic chains are 1-ethyl-3-methylpentyl,1,5-dimethylhexyl, 1-methylheptyl, 1,4-dimethylheptyl,1,2,2-trimethylpropyl, 2-ethylbutyl, 1-propylbutyl, 1,2-dimethylbutyl,2-methylpentyl, 1-ethylpentyl, 1,4-dimethylpentyl, 1-methylhexyl,3-methylhexyl, 1,3,3-trimethylbutyl, 1-methylnonyl. The substitutedammonium ion represented by A preferably has one fatty alkyl group asdescribed above, the remaining groups being preferably H or C₁₋₄ -alkyl,especially H or methyl. Suitable ammonium ions include2-ethylhexylammonium, 1,1,3,3-tetramethylbutylammonium and3,5,5-trimethylhexylammonium.

In compounds of the Formula (1) each of the peripheral carbon atoms inthe 1 to 16 positions of the phthalocyanine nucleus are attached to agroup Y and each Y is independently selected from --H, halogen, --SO₃ Ain which A is as hereinbefore defined, and OR in which R is a pendantorganic radical as hereinbefore defined.

According to a further feature of the present invention there isprovided a process for the generation of singlet oxygen by irradiationin the presence of oxygen of a substituted phthalocyanine, in which atleast one of the peripheral carbon atoms in the 1-16 positions of thephthalocyanine nucleus (M_(R) Pc), as shown in Formula (1), wherein Mand k are as hereinbefore defined, is linked via an oxygen atom to anorganic radical, the remaining peripheral carbon atoms beingunsubstituted or substituted by any combination of atoms or groups andsulphonated derivatives thereof with electromagnetic radiation ofwavelength from 650 to 800 nm. Suitable sources of electromagneticradiation includes sunlight and lasers with emissions in the 650-800 nmregion.

According to a further feature of the present invention there areprovided phthalocyanine compounds of the Formula (2):

    M.sub.k Pc(O--R).sub.a X.sub.b (SO.sub.3 A).sub.d          Formula ( 2)

wherein:

M_(k) Pc is a phthalocyanine nucleus as defined in Formula (1);

each R independently is an organic radical;

each X independently is halogen or hydrogen; the O--R and X groups beingattached to one or more of the 16 peripheral carbon atoms of thephthalocyanine nucleus;

A is selected from H, a metal, ammonium or substituted ammonium asdescribed above;

a is from 1 to 16;

b is from 0 to 15;

d is an average value from 0.1 to 50;

a+b is from 1 to 16; except for CuPc(O-Ph)₄ Cl₁₂ sulphonic acidcontaining 9.3% S and the sodium salt thereof.

In phthalocyanines of Formula (2) M is any of the metals, halometalgroups, hydroxymetal groups or oxymetal groups described above for M. Itis preferred that when M is Cu, R is phenyl, a is 4, and b is 12, that dis an average of from 0.1 to 5.2 or from 5.6 to 50.

In phthalocyanines of Formula (2) it is preferred that M is Ba, Li, Na,K, Mg( ClAl, OHAl, Ca, Zn, ClGa, H, Pt, Pd, OHRh and it is especiallypreferred that M is Zn, H, ClAl, OHAl, Pt, Pd, ClGa, OHRh and BrIn.

In a phthalocyanine of Formula (2) each of the radicals denoted by R maybe selected from any of the pendant organic radicals hereinbeforedefined in relation to Formula (1) above.

In a phthalocyanine of Formula (2) it is preferred that a is from 4 to16 and more preferably from 5 to 16. It is especially preferred that ais 16.

In a phthalocyanine of Formula (2) each halogen denoted by X ispreferably independently selected from --F, --Cl, --Br and --I and it isespecially preferred that each halogen denoted by X is independently--Cl or --Br.

In a phthalocyanine of Formula (2) it is preferred that b is from 0 to12, and more preferably from 0 to 11.

When a+b is <16 the remainder of the 16 peripheral carbon atoms, notcarrying a group O--R or X, may carry a sulphonate group, --SO₃ A or agroup represented by R. It is however preferred that the sum of a+b is16. It is also preferred that a is 4, 8, 12 or 16 and especially 8, 12or 16.

In phthalocyanines of Formula (2) the metal ion denoted by A ispreferably an alkali or alkaline earth metal ion and more preferably isselected from lithium, sodium and potassium ion. It is especiallypreferred that A is a sodium, an ammonium ion or hydrogen.

In phthalocyanines of Formula (2) it is preferred that d is an averagevalue from 2 to 40. It is more preferred that d is an average value from2 to 30, especially preferred that d is an average value from 16 to 30.

A preferred sub-group of compounds of Formula (2) are those in which Mis Zn, ClAl, OHAl, R is phenyl, 2-, 3- or 4-methylphenyl or naphth-2-yl,a is from 1 to 16, X is halogen, b is from 0 to 15, a+b is equal to 16,A is as hereinbefore defined and d is an average value from 10 to 30. Anespecially preferred sub-group of compounds of Formula (2) are those inwhich M is Zn, R is phenyl, 2-, 3- or 4-methylphenyl or naphth-2-yl, ais 4, 12 or 16, b is 12, 4 or 0, a+b is equal to 16, A is ashereinbefore defined and d is an average value from 12 to 30.

According to a further feature of the present invention there areprovided phthalocyanine compounds of the Formula (3) free from sulphonicacid groups:

    M.sub.k Pc(O--R.sup.1).sub.a X.sub.b                       Formula ( 3)

wherein:

M_(k) Pc is as defined in Formula (1);

R¹ is selected from optionally substituted aryl and optionallysubstituted heteroaryl;

X is halogen or H;

a is an integer from 1 to 16;

b is an integer from 0 to 15; and a+b is equal to 16;

except for the compounds:

VOPc(4-CH₃ Ph--O)H₁₅

H₂ Pc(4-(CH₃)₂ PhC--Ph--O)H₁₅

CuPc(4-BuPh--O)₄ H₁₂

H₂ Pc(4-BuPh--O)₄ H₁₂

CuPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

NiPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

PdPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

PtPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

ZnPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

CoPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

FePc(4-(CH₃)₂ PhC--Ph-)₄ H₁₂

MnPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

H₂ Pc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

MgPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

PbPc(4-(CH₃)₂ PhC--Ph--O)₄ H₁₂

CuPc(Ph--O)₄ H₁₂

ZnPc(Ph--O)₄ H₁₂

H₂ Pc(Ph-H)₄ H₁₂

VOPc(Ph--O)₄ H₁₂

SnCl₂ Pc(Ph--O)₄ H₁₂

ZnPc(4-NO₂ Ph--O)₄ H₁₂

ZnPc(4-NH₂ Ph--O)₄ H₁₂

H₂ Pc(4-NH₂ Ph--O)₄ H₁₂

ZnPc(4-OHPh--O)₄ H₁₂

H₂ Pc(4-OHPh--O)₄ H₁₂

NiPc(2,3,5-(Me)₃ Ph--O)₄ H₁₂

PbPc(2-Br-4-EtPh--O)₄ H₁₂

VOPc(2-Br-4-EtPh--O)₄ H₁₂

PbPc(2-Br-4-Me(CH₂)₄ Ph--O)₄ H₁₂

MgPc(2-Br-4-Me(CH₂)₄ Ph--O)₄ H₁₂

ZnPc(4-Me(CH₂)₆ Ph-)₄ H₁₂

ClAlPc(2-Br-4-Me(CH₂)₃ Ph--O)₄ H₁₂

PbPc(2-Br-4-Me(CH₂)₃ Ph--O)₄ H₁₂

CuPc(2-naphthyl-O)₈ H₈

CoPc(2-naphthyl-O)₈ H₈

ClAlPc(2-naphthyl-O)₈ H₈

Li₂ Pc(2-naphthyl-O)₈ H₈

TiOPc(2-naphthyl-O)₈ H₈

CuPc(Ph--O)₈ H₈

ClGaPc(Ph--O)₈ H₈

CuPc(4-EtPh--O)₈ H₈

H₂ Pc(4-MeOPh--O)₈ H₈

CuPc(Ph--O)₄ Cl₁₂

CuPc(4-ClPh--O)₄ Cl₁₂

CuPc(4-CH₃ Ph--O)₄ Cl₁₂

CuPc(4-Ph-Ph--O)₄ Cl₁₂

CuPc(4-BuPh--O)₄ Cl₁₂

CuPc(Ph--O)₈ Cl₈

ClGaPc(Ph--O)₈ Cl₈

ClAlPc(2-naphthyl-O)₈ Cl₈

CuPc(Ph--O)₁₆

H₂ Pc(Ph--O)₁₆

BrAlPc(Ph--O)₁₆

ClGaPc(Ph--O)₁₆

VOPc(Ph--O)₁₆

BrAlPc(4-ClPh--O)₁₆

H₂ Pc(4-CH₃ Ph--O)₁₆

CuPc(2-naphthyl-)₁₆

VOPc(2-naphthyl-O)₁₆

SnOPc(2-naphthyl-O)₁₆

ClInPc(2-naphthyl-O)₁₆

According to a further feature of the present invention there areprovided phthalocyanine compounds of the Formula (3):

(1) wherein

M is selected from Na, Ca, ClSc, OHSc, Cr, ClCr, OHCr, Rh, ClRh, OHRh,Sn, Ba, Ir, Sn, ClSm, OHSm, OHAl, SiCl₂, SiO and Si(OH)₂.

(2) wherein:

M is selected from Li, Na, Mg, Al, OHAl, Ca, Mn, Fe, Co, Zn, Ga, SiCl₂,SiO, Si(OH)₂ ;

X is halogen;

a is 4, 8, 12 or 16; and b is 12, 8, 4 or 2.

(3) wherein:

M is selected from H, BrAl, ClGa, ClIn, VO, SnO, Li, Na, Mg, Al, OHAl,Ca, Mn, Fe, Co, Zn, Ga, SiCl₂, SiO, Si(OH)₂ ;

X is halogen;

a is 4, 8 or 12; and b is 12, 8 or 4.

(4) wherein:

M is selected from BrAl, ClIn, SnO, Na, Al, OHAl, Ca, SiCl₂, SiO andSi(OH)₂ ;

X is hydrogen;

a is 4, 8 or 12; and b is 12, 8 or 4.

(5) wherein:

M is selected from Na, Mg, Al, OHAl, Ca, Mn, Ni, Fe, Zn, SiCl₂, SiO andSi(OH)₂ ;

X is hydrogen;

a is 8 or 12; and b is 8 or 4.

(6) wherein:

M is selected from Zn, Mg, Fe, Mn, Pd, Pt, TiO, Ni, Pb, and SnCl₂ ;

a is from 5 to 16; and b is from 11 to 0.

(7) wherein:

M is selected from Zn, Mg, Fe, Mn, Pd, Pt, TiO, Ni, and SnCl₂ ;

a is from 1 to 3, and b is from 15 to 3.

(8) wherein:

M is selected from Zn, Li, Mg, Na, OHAl, Ca, Fe, Mn, Co, Ni, Pb, SnCl2and VO;

X is halogen;

a is from 1 to 16; and b is from 15 to 0.

(9) wherein:

a is from 1 to 14; and b is from 15 to 2, provided that at least one Xis H and one X is halogen.

(10) wherein:

M is H;

X is halogen;

a is from 1 to 15 and b is from 15 to 1.

(11) wherein:

M is H; and

a is 16 provided that R¹ is not Ph or 4-MePh.

(12) wherein

M is BrAl; and

a is 16 provided that R¹ is not Ph or 4Cl-Ph.

(13) wherein:

M is ClAl;

X is halogen;

a is from 1 to 7 or from 9 to 16; and b is from 15 to 9 or from 9 to 0.

(14) wherein:

M is ClAl;

a is 8; b is 8; provided that R¹ is not 2-naphthyl.

(15) wherein:

M is Li;

a is from 0 to 16; b is 15 to 0; provided that R¹ is not 2-naphthyl.

In a phthalocyanine of Formula (3) it is preferred that each of theradicals denoted by R¹ is independently selected from mono- or bi-cyclicaromatic or heteroaromatic radicals. Examples of suitable aromatic andheteroaromatic radicals are those described above for R. The radicalsdenoted by R¹ are more preferably phenyl or naphthyl, especially2-naphthyl. Preferred substituents for the R¹ group are as described forR.

In a phthalocyanine of Formula (3) it is preferred that a is an integerfrom 4 to 16 and that b is an integer from 12 to 0. It is also preferredthat a is 4, 8, 12 or 16, more especially 8, 12 or 16, and that b is 12,8, 4 or 0.

In a phthalocyanine of Formula (3) it is preferred that the metaldenoted by M is Zn, ClAl, OHAl, ClRh, OHRh, ClIn, BrIn, OHIn, ClGa,OHGa, Pt, Pd, Li, Na, K, Ca, Ba, Mg, ClSc or OHSc.

It is especially preferred in phthalocyanines of Formula (3) that M isZn, ClAl, OHAl, R¹ is phenyl or 2-naphthyl, a is 16, ClRh, OHRh, BrIn,OHIn, ClGa, OHGa, Pt or Pd.

A preferred sub-group of compounds of Formula (3) are those in which Mis Zn or Mg, R¹ is phenyl, 2-, 3- or 4-methylphenyl or naphth-2-yl and ais 16. A further preferred sub-group of compounds of Formula (3) arethose in which M is Zn, Mg, ClAl or OHAl, R¹ is phenyl, 2-, 3- or4-methylphenyl or naphth-2-yl, a is 4, X is halogen and b is 12. Afurther preferred sub-group of compounds of Formula (3) are those inwhich M is Zn or Mg, R¹ is phenyl, 2-, 3- or 4-methylphenyl ornaphth-2-yl, a is 8, X is H or halogen and b is 8. A further preferredsub-group of compounds are Formula (3) are those in which M is Zn, Mg,OHAl, ClAl, R¹ is phenyl, 2-, 3- or 4-methylphenyl or naphth-2-yl, a is12, X is H or halogen and b is 8.

The phthalocyanines of Formula (1), Formula (2) and Formula (3) can beprepared by the following methods:--

(a) by reaction of a 1,2-dicyanobenzene of Formula (4): ##STR3##wherein: Z is selected from chloro, bromo and iodo;

e is an integer from 0 to 3;

f is an integer from 1 to 4; and

e+f is equal to 4 with a compound R--OH whereby up to 4 of the groups,Z, are replaced by R--O groups to form a compound of Formula (5):##STR4## wherein: Z is as described above;

R is as described above for compounds of Formula (2);

g is an integer from 0 to 3;

h is an integer from 0 to 3;

i is an integer from 1 to 4; and

g+h+i is equal to 4. followed by reaction of one or more1,2-dicyanobenzene compounds of Formula (5), or a combination of one ormore compounds of Formula (5) and 1,2-dicyanobenzene, with anappropriate metal or metal salt optionally in an inert liquid at anelevated temperature to form a phthalocyanine of Formulae (1), (2) or(3). The presence of at least one equivalent of 1,2-dicyanobenzene isrequired for the preparation of Formulae (2) and (3) where X is H and bis 13, 14 or 15.

(b) by reaction at elevated temperatures of a compound of Formula (6):

    M.sub.k Pc Z.sub.(a+b)                                     Formula ( 6)

M_(k), Pc, Z, a and b are as described above with a compound, R--OH, ina polar organic medium preferably in the presence of an acid binder.

The reactions in (a) above are more fully described in UK patent numbers1489394 and 2200650 and German patent number 2455675, reaction (b) ismore fully described in our co-pending UK patent application number9023893.2 (incorporated by reference herein).

In reactions of type (b) the polar organic medium which may or may notbe a liquid at ambient temperature and which may only partially dissolvethe reactants, preferably has a boiling point from 80° C. to 300° C.,more preferably from 150° C. to 200° C. The polar organic medium ispreferably inert or may act to catalyse the reaction. It is preferredthat the polar organic medium is selected from N-methyl-2-pyrrolidone,dimethylformamide, methylcyclohexanol, octanol, benzyl alcohol,nitrobenzene and quinoline. It is especially prefrred that in reactionsof type (b) that the polar organic medium is dimethylformamide orN-methyl-2-pyrrolidone.

In reactions of type (b) the acid binder is preferably selected fromalkali metal hydroxides and carbonates. It is preferred that the acidbinder is lithium, sodium or potassium hydroxide, it is especiallypreferred that the acid binder is potassium hydroxide.

The sulphonated phthalocyanines of Formula (2) can be prepared bysulphonating a precursor of a phthalocyanine of Formula (2) in which dis 0, using sulphuric acid which may contain excess SO₃ (oleum). Thestrength of acid may vary within wide limits from 1% sulphuric acid upto 30% oleum. It is preferred that the strength of acid is from 50%sulphuric acid up to 30% oleum, it is especially preferred that thestrength of acid is from 98% sulphuric to 30% oleum. The reactiontemperature may vary from -10° C. to 60° C. depending on the extent ofsulphonation required. Sulphonation may be performed in an inert liquid.

As the concentration of the sulphuric acid or the oleum is increased ata fixed reaction temperature, more sulphonic acid groups are introducedinto the phthalocyanine. Similarly as the reaction temperature isincreased at a particular acid strength, more sulphonic acid groups areintroduced into the phthalocyanine.

In the sulphonation reaction a preferred acid is 10% oleum and apreferred reaction temperature is from -10° C. to 40° C., especiallyfrom 10° C. to 25° C.

The phthalocyanines can be sulphonated directly on the Pc nucleus,particularly when any of the 1-16 positions is unsubstituted (i.e. the1-16 peripheral carbon atoms carry a hydrogen atom) or on any of thependant organic groups R or R¹, or on both the Pc nucleus and thependant organic groups.

The phthalocyanines of particular interest are those which promote thegeneration of singlet oxygen when exposed to radiation from the 650 nmto 800 nm region, especially the 680 to 770 nm region of theelectromagnetic spectrum.

Singlet oxygen has a greater energy than ground-state, triplet oxygen.The singlet and triplet states of oxygen are distinguished by thesinglet state having two electrons of anti-parallel spins and thetriplet state having an uncoupled pair of electrons with parallel spins.The singlet oxygen is also distinguished from triplet oxygen because itis a highly reactive species with a lifetime from a few microseconds toseveral hundred microseconds. During its lifetime singlet oxygen has thepotential to react before being deactivated. The reactivity of thesinglet oxygen may be utilised in a wide range of applications whichinclude photobleaching, photodeodorising, photodynamic therapy (PDT),treatment of visible stains on a range of material surfaces, surfacesinclude fabric, cement, stone, brick, glass, etc., biocidal, degradationof plastics, paper and pulp bleaching, environmental clean-up,anti-microbial action on fibres, incorporation into various products forexample in fabrics as deodorisers, into paints or film treatments todestroy micro-organisms or contaminants, into cement products, glassproducts and paints to confer self-cleaning properties, sterilisingswimming pools and as a surface treatment to preventyellowing/discoloration of paper. For photobleaching andphotodeodorising application the present phthalocyanine can beincorporated into detergent formulations which are used in a wide rangeof cleaning applications.

According to a further feature of the present invention there isprovided a process for removing stains from fabrics which comprisestreating the stained fabrics with an aqueous composition comprising atleast one compound of Formula (1), Formula (2) or Formula (3) thefabrics being exposed to daylight during or following the treatment.

The aqueous composition may also comprise detergents such as soap orsynthetic detergents, other detergent additives such as soil suspendingagents, optical brightening agents, sud or foam control agents, perfume,surfactants such as alkyl sulphonates, paraffin sulphonates andalkylbenzene sulphonates, ethoxylated alcohols or betaines, and alkalinedetergency builders such as sodium carbonate, silicate, orthophosphatesand polyphosphates.

The process for removing stains is preferably carried out attemperatures from 10° C. to 80° C., more preferably from 20° C. to 60°C. and especially from 35° C. to 45° C. Suitable process times for stainremoval are typically from 5 minutes to 5 hours, preferably from 10minutes to 1 hour.

The aqueous composition preferably contains from 0.0005 g to 0.1 g perliter of compounds of Formula (1), Formula (2) and/or Formula (3), morepreferably from 0.001g/l to 0.01 g/l.

The efficacy of the stain removal process generally depends on theconcentration of compounds of Formula (1), Formula (2) and/or Formula(3) in the wash solution, the intensity of daylight, the processtemperature and the process time. The process is generally moreeffective with higher concentrations of compounds of Formula (1),Formula (2) and/or Formula (3), at higher intensities of daylight athigher process temperatures and with longer process times.

The preferred compounds of Formula (2) and Formula (3) are those whereM_(k) is Zn, Co, Fe, Ca, ClAl, OHAl, and H² ; R or R¹ is phenyl and2-naphthyl; a is 16; and d is from 16 to 30.

According to a further feature of the present invention there areprovided compounds of the Formulae (1), (2) and (3) for use intherapeutic treatment of a human or an animal body.

According to a further feature of the present invention, compounds ofFormula (1), Formula (2) or Formula (3) are used for the manufacture ofa medicament for use in the treatment of skin and subcutaneous cancersby photodynamic therapy.

In this treatment the compound of Formula (1), Formula (2) or Formula(3) is introduced into the affected tissue and then irradiated withelectromagnetic radiation in the region from 650-800 nm, preferably680-770 nm in order to generate singlet oxygen which destroys theaffected cells.

The phthalocyanine compounds of the present invention promote theformation of singlet oxygen under the influence of electromagneticradiation, particularly in the 680-770 nm region and are capable ofpromoting singlet oxygen formation in localised areas.

Measurement of triplet oxygen yields after laser excitation and singletoxygen emission yields allows calculation of singlet oxygen generatingefficiency (SΔ). The experimental details for these measurements aremore fully described in Gorman et al, Journal of the American ChemicalSociety 1987!, 109, 3091; Gorman et al, Journal of the American ChemicalSociety 1989!, 111, 1876 and Gorman et al, Photochemistry andPhotobiology 1987! 45(2), 215.

The invention is further illustrated by the following examples in whichall parts and percentages are by weight unless otherwise indicated.

EXAMPLE 1

Preparation of hexadeca(phenoxy) dihydrophthalocyanine

(i) Preparation of 1,2-dicyano-3,4,5,6-tetraphenoxybenzene

A mixture of 1,2-dicyano-3,4,5,6-tetrachlorobenzene (50 parts), phenol(106 parts), potassium carbonate (104 parts) and dimethylformamide (200parts) was stirred and heated at 70° C. for 2 hours before pouring intowater (500 parts). The aqueous mixture was extracted with chloroform(2×300 parts). The chloroform extract was washed with a 5% aqueoussolution of sodium hydroxide (2×250 parts) and then with water (2×250parts). The chloroform extract was dried over anhydrous magnesiumsulphate, filtered and the chloroform was removed by distillation underreduced pressure to leave a brown oil. The brown oil was dissolved inhot butan-1-ol and allowed to cool slowly.1,2-Dicyano-3,4,5,6-tetraphenoxybenzene (62.2 parts, 67%) was obtainedas a pale yellow solid m.p. 149°-151° C.

(ii) Preparation of hexadeca(phenoxy) dilithium phthalocyanine

Lithium (0.42 parts) was dissolved in butan-1-ol (50 parts) withstirring at 100° C. over 4 hours before adding1,2-dicyano-3,4,5,6-tetra(phenoxy)benzene (10 parts). The reactionmixture was stirred at 120° C. for 30 minutes. The solution was cooledand a green solid was collected by filtration. The solid was washed withmethanol (3×50 parts) and dried to give hexadeca(phenoxy)dilithiumphthalocyanine (5.5 parts) m.p.>250° C.

(iii) Preparation of hexadeca(phenoxy) dihydrophthalocyanine

A mixture of hexadeca(phenoxy) dilithium phthalocyanine (3.0 parts) andtoluene (100 parts) was stirred at 20° C. and p-toluene sulphonic acid(1.14 parts) was added slowly. The reaction mixture was stirred at 20°C. for 30 minutes before adding activated carbon and filtering throughClarcel flo filter aid. After filtering the solution was passed througha silica gel column washing with toluene. The solvent was removed bydistillation under reduced pressure to leave a green solid. The solidwas stirred in methanol (50 parts), filtered off and washed with waterand dried to give hexadeca(phenoxy) dihydrophthalocyanine (2.68 parts)m.p.>250° C.

EXAMPLE 2

Preparation of hexadeca(phenoxy) zinc phthalocyanine

A mixture of 1,2-dicyano-3,4,5,6-tetra(phenoxy)benzene (20 parts), zincchloride (1.81 parts), urea (0.8 parts) and nitrobenzene (40 parts) wasstirred at 180° C. for 2 hours before pouring into ethanol (74 OP, 200parts), aqueous hydrochloric acid (2 mol.dm⁻³, 600 parts), aqueousammonia (2 mol.dm⁻³, 300 parts), water (2×200 parts) and ethanol (74 OP,500 parts). The solid was dried to give hexadeca(phenoxy) zincphthalocyanine (4.4 parts) m.p.>250° C.

EXAMPLE 3

Preparation of hexadeca(phenoxy) chloroaluminium phthalocyanine

A mixture of 1,2-dicyano-3,4,5,6-tetra(phenoxy)benzene (4.13 parts),urea (0.17 parts), anhydrous aluminium chloride (0.37 parts) andammonium molybdate (0.004 parts) was stirred at 200° C. for 30 minutesand cooled to give a brown solid. The solid was broken up and slurriedin ethanol (74 OP, 200 parts). A green solid was collected by filtrationand washed with ethanol (100 parts) before slurrying it with aqueoushydrochloric acid (2 mol.dm⁻³, 200 parts) and filtering. The solid waswashed with aqueous ammonia (2 mol.dm⁻³, 100 parts), water (200 parts)and ethanol (74 OP, 300 parts). The solid was slurried in hot ethanol(74 OP, 2×200 parts), collected and dried to give hexadeca(phenoxy)chloroaluminium phthalocyanine (1.17 parts) m.p. 152°-154° C.

EXAMPLE 4

Preparation of hexadeca(phenoxy) magnesium phthalocyanine

The procedure of Example 3 was used except that magnesium chloridehexahydrate (0.56 parts) was used in place of the anhydrous aluminiumchloride. Hexadeca(phenoxy) magnesium phthalocyanine (1.57 parts) wasobtained as a green solid, m.p.>250° C.

EXAMPLE 5

Preparation of hexadeca(phenoxy) copper (II) phthalocyanine

The procedure of Example 3 was used except that copper (II) chloride(0.34 parts) was used in place of the anhydrous aluminium chloride.Hexadeca(phenoxy) copper (II) phthalocyanine (3.6 parts) was obtained asa green solid, m.p.>250° C.

EXAMPLE 6

Preparation of hexadeca(phenoxy) nickel (II) phthalocyanine

The procedure of Example 3 was used except that nickel (II) chloride(0.36 parts) was used in place of the anhydrous aluminium chloride.Hexadeca(phenoxy) nickel (II) phthalocyanine (1.1 parts) was obtained asa green solid, m.p.>250° C.

EXAMPLE 7

Preparation of hexadeca(2-naphthoxy)dilithium phthalocyanine

(i) Preparation of 1,2-dicyano-3,4,5,6-tetra(2-naphthoxy)benzene1,2-Dicyano-3,4,5,6-tetrachlorobenzene (30.5 parts), potassium carbonate(62.8 parts) and 2-naphthol (98.1 parts) were stirred indimethylformamide (140 parts) at 70° C. for 3 hours. The mixture waspoured into water (300 parts) and extracted with chloroform (3×300parts). The combined chloroform extracts were washed with dilute aqueoussodium hydroxide solution (500 parts) and then with water (500 parts).The chloroform was dried over anhydrous magnesium sulphate beforeevaporating under reduced pressure to leave a brown liquid whichcrystallised on adding butan-1-ol, cooling and standing for 2 hours. Thecrystallised solid was filtered, washed with butan-1-ol until thefiltrates were colourless. The solid was dried to give1,2-dicyano-3,4,5,6-tetra(2-naphthoxy)benzene (40.6 parts), m.p.188°-190° C.

(ii) Preparation of hexadeca(2-naphthoxy) dilithium phthalocyanine

The procedure of Example 1(ii) was used except that1,2-dicyano-3,4,5,6-tetra(2-naphthoxy)benzene (10 parts) was used inplace of the 1,2-dicyano-3,4,5,6-tetra(phenoxy)benzene and 0.3 partsinstead of 0.42 parts of lithium were used. Hexadeca(2-naphthoxy)dilithium phthalocyanine (5.71 parts) was obtained as a green solid,m.p. 185°-190° C.

EXAMPLE 8

Preparation of hexadeca(2-naphthoxy) zinc phthalocyanine

The procedure of Example 2 was used except that1,2-dicyano-3,4,5,6-tetra(2-naphthoxy)benzene (20 parts) was used inplace of the 1,2-dicyano-3,4,5,6-tetra(phenoxy)benzene and 1.29 partsinstead of 1.81 parts of zinc chloride and 0.57 parts instead of 0.8parts of urea were used. Hexadeca(2-naphthoxy) zinc phthalocyanine (15.4parts) was obtained as a green solid, m.p. 230°-235° C.

EXAMPLE 9

Preparation of hexadeca(phenoxy)dihydrophthalocyanine eicosa (sulphonicacid) sodium salt

Hexadeca(phenoxy)dihydrophthalocyanine (1.0 parts) was added to 10%oleum (2.3 parts) at 0° C. over 15 minutes. The mixture was allowed towarm to 200° C. and was stirred for 3 hours before pouring into amixture of ice and water (100 parts). The resultant solution wasneutralised to pH 7 using 48% aqueous sodium hydroxide. The product waspurified by dialysing the neutralised solution in Visking tubing(obtainable from The Scientific Instrument Centre, Eastleigh, Hampshire)over 24 hours. The dialysed solution was evaporated to leave hexadeca(phenoxy)dihydrophthalocyanine eicosa (sulphonic acid) sodium salt (2.0parts) as a black solid, m.p. 230°-235° C.

EXAMPLE 10

Preparation of hexadeca(2-naphthoxy) dihydro phthalocyanine triaconta(sulphonic acid) sodium salt

The procedure of Example 9 was used except that 2.6 parts instead of 2.3parts of 10% oleum was used. Hexadeca(phenoxy)dihydro phthalocyanineeicosa(sulphonic acid) sodium salt was obtained as a black solid,m.p.>250° C.

EXAMPLE 11

Preparation of hexadeca(phenoxy) zinc phthalocyanine hexadeca(sulphonicacid) sodium salt

The procedure of Example 9 was used except that hexadeca(phenoxy) zincphthalocyanine (1.4 parts) was used in place of the hexadeca(phenoxy)dihydro phthalocyanine and 3.5 parts of 10% oleum was used instead of2.3 parts. Hexadeca(phenoxy) zinc phthalocyanine hexadeca(sulphonicacid) sodium salt (1.32 parts) was obtained as a green solid, wasobtained as a green solid, m.p.>250° C.

EXAMPLE 12

Preparation of hexadeca(2-naphthoxy) zinc phthalocyaninetriaconta(sulphonic acid) sodium salt

The procedure of Example 9 was used except that hexadeca(2-naphthoxy)zinc phthalocyanine (1.0 parts) was used in place of thehexadeca(phenoxy) dihydro phthalocyanine and 3.0 parts of 10% oleum wasused instead of 2.3 parts. Hexadeca(2-naphthoxy) zinc phthalocyaninetriaconta(sulphonic acid) sodium salt (1.7 parts) was obtained as agreen solid, m.p.>250° C.

EXAMPLE 13

Preparation of hexadeca(2-naphthoxy)hydroxyaluminium phthalocyaninetriaconta(sulphonic acid) sodium salt

(i) Preparation of hexadeca(2-naphthoxy)chloroaluminium phthalocyanine

The procedure of Example 3 was used except that1,2-dicyano-3,4,5,6-tetra(2-naphthoxy)benzene (3.0 parts) was used inplace of the 1,2-dicyano-3,4,5,6-tetra(phenoxy)benzene, 0.20 partsinstead of 0.37 parts of anhydrous aluminium chloride and 0.09 partsinstead of 0.17 parts of urea were used. Hexadeca(2-naphthoxy)chloroaluminium phthalocyanine (2.43 parts) was obtained as abrown-green solid, m.p. 208°-210° C.

(ii) Preparation of hexadeca(2-naphthoxy) hydroxyaluminiumphthalocyanine triaconta(sulphonic acid) sodium salt

The procedure of Example 9 was used except that hexadeca(2-naphthoxy)chloroaluminium phthalocyanine (1.0 parts) was used in place of thehexadeca(phenoxy) dihydro phthalocyanine. Hexadeca(2-naphthoxy) zincphthalocyanine triaconta(sulphonic acid) sodium salt (1.7 parts) wasobtained as a green solid, m.p.>250° C.

EXAMPLE 14

Preparation of hexadeca(phenoxy) hydroxyaluminium phthalocyaninehexadeca(sulphonic acid) sodium salt

The procedure of Example 9 was used except that hexadeca(phenoxy)chloroaluminium phthalocyanine (0.4 parts) was used in place of thehexadeca(phenoxy) dihydro phthalocyanine, 3.0 parts instead of 2.3 partsof 10% oleum was used. Hexadeca(phenoxy) hydroxyaluminium phthalocyaninehexadeca(sulphonic acid) sodium salt (0.63 parts) was obtained as agreen solid, m.p.>250° C.

EXAMPLE 15

Preparation of hexadeca(2-naphthoxy) dihydro phthalocyaninetriaconta(sulphonic acid) sodium salt

(i) Preparation of hexadeca(2-naphthoxy) dihydro phthalocyanine

The procedure of Example 1(iii) was used except thathexadeca(2-naphthoxy) dilithium phthalocyanine (3.0 parts) was used inplace of the hexadeca(phenoxy) dilithium phthalocyanine and 0.82 partsinstead of 1.14 parts of p-toluene sulphonic acid were used.Hexadeca(2-naphthoxy) dihydro phthalocyanine (0.75 parts) was obtainedas a black solid, m.p. 220°-225° C.

(ii) Preparation of hexadeca(2-naphthoxy) dihydro phthalocyaninetriaconta(sulphonic acid) sodium salt

The procedure of Example 9 was used except that hexadeca(2-naphthoxy)dihydro phthalocyanine (1.0 parts) was used in place of thehexadeca(phenoxy) dihydro phthalocyanine, 3.0 parts instead of 2.3 partsof 10% oleum was used. Hexadeca(2-naphthoxy) dihydro phthalocyaninetriconta(sulphonic acid) sodium salt (1.5 parts) was obtained as a greensolid, m.p.>250° C.

EXAMPLE 16

Preparation of hexadeca(phenoxy) palladium phthalocyanine

The procedure of Example 2 was used except that palladium (II) chloride(2.4 parts) was used in place of the zinc chloride. Hexadeca (phenoxy)palladium phthalocyanine was obtained as a green solid, m.p.>250° C.

EXAMPLE 17

Preparation of hexadeca(phenoxy) palladium phthalocyanine hexadeca(sulphonic acid) sodium salt

The procedure of Example 9 was used except that hexadeca(phenoxy)palladium phthalocyanine was used in place of the hexadeca(phenoxy)dihydro phthalocyanine. Hexadeca(phenoxy) palladium phthalocyaninehexadeca(sulphonic acid) sodium salt was obtained as a green solid,m.p.>250° C.

EXAMPLE 18

Preparation of hexadeca(phenoxy) platinum phthalocyanine

The procedure of Example 2 was used except that platinum (II) bromide(4.7 parts) was used in place of the zinc chloride. Hexadeca (phenoxy)platinum phthalocyanine was obtained as a green solid, m.p.>250° C.

EXAMPLE 19

Preparation of hexadeca(phenoxy) platinum phthalocyanine hexadeca(sulphonic acid) sodium salt

The procedure of Example 9 was used except that hexadeca(phenoxy)platinum phthalocyanine was used in place of the hexadeca(phenoxy)dihydro phthalocyanine. Hexadeca(phenoxy) platinum phthalocyaninehexadeca(sulphonic acid) sodium salt was obtained as a green solid,m.p.>250° C.

EXAMPLE 20

Preparation of hexadeca(phenoxy) chlororuthenium phthalocyanine

The procedure of Example 2 was used except that ruthenium (III) chloride(2.8 parts) was used in place of the zinc chloride. Hexadeca (phenoxy)chlororuthenium phthalocyanine was obtained as a green solid, m.p.>250°C.

The 1,2-dicyanobenzenes of Examples 24-36 are not a feature of thepresent invention but are used as intermediates in the preparation ofphthalocyanines described below.

EXAMPLES 24 to 30

Further 1,2-dicyanobenzenes compounds of Formula (5) were prepared bythe method of Example 1i) using equimolar amounts of the appropriatesubstituted phenol in place of phenol as described in Example 1i).

    ______________________________________                                        Example  Starting Phenol                                                                            Product 1,2-dicyanobenzene                              ______________________________________                                        24       2-methylphenol                                                                             3,4,5,6-tetra(2-methylphenoxy)                          25       3-methylphenol                                                                             3,4,5,6-tetra(3-methylphenoxy)                          26       4-methylphenol                                                                             3,4,5,6-tetra(4-methylphenoxy)                          27       4-methoxyphenol                                                                            3,4,5,6-tetra(4-methoxyphenoxy)                         28       1-naphthol   3,4,5,6-tetra(1-naphthoxy)                              29       2-naphthol   3,4,5,6-tetra(2-naphthoxy)                              30       4-chlorophenol                                                                             3,4,5,6-tetra(4-chlorophenoxy)                          ______________________________________                                    

EXAMPLE 31

Preparation of 4-chloro-1,2-dicyano-3,5,6-tri(4-methylphenoxy)benzene

The procedure of Example 1i) was followed except that 4-methyl phenol(121.8 parts) was used in place of the phenol.4-Chloro-1,2-dicyano-3,5,6-tri(4-methylphenoxy)benzene (43.7 parts) wasobtained as a pale green solid, m.p. 142°-145° C.

EXAMPLES 32 and 33

Further 1,2-dicyanobenzenes in accordance with Formula (6) were preparedby the method of Example 21 using equimolar amounts of the appropriatephenol in place of the phenol described in Example 31.

    ______________________________________                                        Example  Starting Phenol                                                                            Product 1,2-dicyanobenzene                              ______________________________________                                        32       4-methoxyphenol                                                                            4-chloro-3,5,6-                                                               tri(4-methoxyphenoxy)                                   33       4-nitrophenol                                                                              4-chloro-3,5,6-tri(4-nitrophenoxy)                      ______________________________________                                    

EXAMPLE 34

Preparation of 3,5,6-trichloro-1,2-dicyano-4-phenoxybenzene

A solution of potassium hydroxide (11.2 parts) in water (22 parts) wasadded dropwise to a stirred solution of3,4,5,6-tetra-chloro-1,2-dicyanobenzene (26.6 parts) and phenol (9.4parts) in acetone (100 parts) at 0° C. The solution was stirred at 60°C. for 2 hours before pouring into water (500 parts). The aqueousmixture was extracted with dichloromethane (3×500 parts). Thedichloromethane extracts were washed with water (3×200 parts), driedover anhydrous Na₂ SO₄, filtered and the dichloromethane was removedunder reduced pressure to leave a brown solid. The solid wasrecrystallised from butan-1-ol.3,5,6-Trichloro-1,2-dicyano-4-phenoxybenzene (17 parts) was obtained asa brown solid, m.p. 147°-150° C.

EXAMPLE 35

Preparation of 1,2-dicyano-3-phenoxybenzene

A solution of 1,2-dicyano-3-nitrobenzene (2.77 parts) and sodiumphenoxide (2.79 parts) in dimethylformamide (50 parts) was stirred at120° C. for 2 hours. The reaction mixture was poured into water andextracted with diethyl ether (100 parts). The diethyl ether extract waswashed with 5% aqueous potassium hydroxide solution (2×200 parts) andwater (2×200 parts) and the diethyl ether was removed under reducedpressure to leave a solid. Recrystallisation of the solid from a 1:1diethyl ether:petroleum spirit (b.pt. 60°-80° C.) gave1,2-dicyano-3-phenoxybenzene (2.1 parts, 60%) as a pale green solid,m.pt. 110°-112° C.

EXAMPLE 36

Preparation of 1,2-dicyano-4-phenoxybenzene

The procedure of Example 35 was followed except that1,2-dicyano-4-nitrobenzene (1.0 part) was used in place of the1,2-dicyano-3-nitrobenzene, 1.0 parts instead of 2.79 parts of sodiumphenoxide and 20 parts instead of 50 parts of dimethylformamide wereused. 1,2-Dicyano-4-phenoxybenzene (0.6 parts, 49%) was obtained as awhite solid, m.pt. 98°-100° C.

EXAMPLES 37-61

Further phthalocyanines of Formula (3) were prepared by the d of Example3 using equimolar amounts of the appropriate 1,2-dicyanobenzene in placeof the 1,2-dicyano-3,4,5,6-tetra(phenoxy)benzene and the appropriateanhydrous metal chloride in place of the anhydrous aluminium chloride:

    __________________________________________________________________________                  Metal                                                                              Product        Yield                                       Example                                                                            1,2-dicyanobenzene                                                                     Chloride                                                                           M   R.sup.1                                                                            a x b %  m.p./°C.                          __________________________________________________________________________    37   as Example 1i)                                                                         RhCl.sub.3                                                                         OHRh                                                                              Ph   16                                                                              --                                                                              --                                                                              30 135-140                                  38   as Example 1i)                                                                         InBr.sub.3                                                                         BrIn                                                                              Ph   16                                                                              --                                                                              --                                                                              56 >250                                     39   as Example 1i)                                                                         ScCl.sub.3                                                                         OHSc                                                                              Ph   16                                                                              --                                                                              --                                                                              22 190-195                                  40   as Example 1i)                                                                         GaCl.sub.3                                                                         ClGa                                                                              Ph   16                                                                              --                                                                              --                                                                              55 >250                                     41   as Example 24                                                                          ZnCl.sub.2                                                                         Zn  2-MePh                                                                             16                                                                              --                                                                              --                                                                              18 >250                                     42   as Example 25                                                                          ZnCl.sub.2                                                                         Zn  3-MePh                                                                             16                                                                              --                                                                              --                                                                              37 139-143                                  43   as Example 26                                                                          ZnCl.sub.2                                                                         Zn  4-MePh                                                                             16                                                                              --                                                                              --                                                                              13 >250                                     44   as Example 24                                                                          AlCl.sub.3                                                                         ClAl                                                                              2-MePh                                                                             16                                                                              --                                                                              --                                                                              27 >250                                     45   as Example 25                                                                          AlCl.sub.3                                                                         ClAl                                                                              3-MePh                                                                             16                                                                              --                                                                              --                                                                              20 205-207                                  46   as Example 26                                                                          AlCl.sub.3                                                                         OHAl                                                                              4-MePh                                                                             16                                                                              --                                                                              --                                                                              26 >250                                     47   as Example 24                                                                          MgCl.sub.2                                                                         Mg  2-MePh                                                                             16                                                                              --                                                                              --                                                                              58 >250                                     48   as Example 25                                                                          MgCl.sub.2                                                                         Mg  3-MePh                                                                             16                                                                              --                                                                              --                                                                              40 132-137                                  49   as Example 26                                                                          MgCl.sub.2                                                                         Mg  4-MePh                                                                             16                                                                              --                                                                              --                                                                              55 223-226                                  50   as Example 30                                                                          ZnCl.sub.2                                                                         Zn  4-ClPh                                                                             16                                                                              --                                                                              --                                                                              21 187-190                                  51   as Example 27                                                                          ZnCl.sub.2                                                                         Zn  4-OMePh                                                                            16                                                                              --                                                                              --                                                                              73 132-135                                  52   as Example 29                                                                          MgCl.sub.2                                                                         Mg  2-Np 16                                                                              --                                                                              --                                                                              24 175-180                                  53   as Example 29                                                                          AlCl.sub.3                                                                         ClAl                                                                              2-Np 16                                                                              --                                                                              --                                                                              79 208-210                                  54   as Example 28                                                                          ZnCl.sub.2                                                                         Zn  1-Np 16                                                                              --                                                                              --                                                                              18 235-240                                  55   as Example 31                                                                          ZnCl.sub.2                                                                         Zn  4-MePh                                                                             12                                                                              Cl                                                                              4 29 175-178                                  56   as Example 31                                                                          MgCl.sub.2                                                                         Mg  4-MePh                                                                             12                                                                              Cl                                                                              4 27 210-213                                  57   as Example 31                                                                          AlCl.sub.3                                                                         ClAl                                                                              4-MePh                                                                             12                                                                              Cl                                                                              4 65 175-178                                  58   as Example 32                                                                          ZnCl.sub.2                                                                         Zn  4-OMePh                                                                            12                                                                              Cl                                                                              4 33 189-191                                  59   as Example 33                                                                          ZnCl.sub.2                                                                         Zn  4-NO.sub.2 Ph                                                                      12                                                                              Cl                                                                              4 15 183-185                                  60   as Example 36                                                                          ZnCl.sub.2                                                                         Zn  Ph   4 H 12                                                                              17 >250                                     61   as Example 35                                                                          ZnCl.sub.2                                                                         Zn  Ph   4 H 12                                                                              13 178-180                                  __________________________________________________________________________

EXAMPLE 62

Preparation of hexadeca(1-naphthoxy) zinc phthalocyanine

A mixture of 1,2-dicyano-3,4,5,6-tetra(1-napthoxy)benzene (7.0 parts),zinc chloride (0.45 parts), urea (0.2 parts) and ammonium molybate(0.004 parts) in nitrobenzene (20 parts) was heated at 180° C. for 2hours before cooling and pouring into ethanol (150 parts, 74 OP). Theprecipitated green solid was collected by filtration, washed withethanol (10 parts, 74 OP) and dried to give hexadeca(1-naphthoxy) zincphthalocyanine (18%), m.p. 235°-240° C.

EXAMPLE 63

Preparation of dodecachlorotetra(phenoxy) zinc phthalocyanine

The method of Example 62 was used except that1,2-dicyano-3,5,6-trichloro-4-phenoxybenzene (3.2 parts) was used inplace of the 1,2-dicyano-3,4,5,6-tetra(2-napthoxy)benzene to givedodecachlorotetra(phenoxy) zinc phthalocyanine (20%), m.p.>250° C.

EXAMPLE 64

Preparation of hexadeca(phenoxy) dilithium phthalocyanine

Lithium (0.2 parts) was dissolved in refluxing propan-2-ol (20 parts)over 3 hours. 1,2-Dicyano-3,4,5,6-tetra(phenoxy)benzene (4.5 parts) wasadded to the refluxing mixture over 5 minutes and the reaction mixturewas refluxed for a further 30 minutes before cooling. Methanol (80parts) was added to the cooled reaction mixture and the precipitatedsolid was collected by filtration, washed with methanol (3×20 parts) anddried. Chloroform (50 parts) was added to the dried solid and themixture was filtered to remove inorganic material. The chloroform wasevaporated under reduced pressure to give hexadeca(phenoxy) dilithiumphthalocyanine (55%), m.p.>250° C.

EXAMPLES 65-68

Further phthalocyanines of Formula (3) were prepared by the method ofExample 64 using equimolar amounts of the appropriate metal in place ofthe Lithium:

    ______________________________________                                                 Product                                                              Example                                                                              Metal   M      R.sup.1                                                                            a   x    b   Yield %                                                                             m.p./°C.                 ______________________________________                                        65     K       K.sub.2                                                                              Ph   16  --   --  22    >250                            66     Na      Na.sub.2                                                                             Ph   16  --   --  24    >250                            67     Ca      Ca     Ph   16  --   --  33    >250                            68     Ba      Ba     Ph   16  --   --  24    >250                            ______________________________________                                    

EXAMPLES 69-75

Further sulphonated phthalocyanines were prepared using the method ofExample 11 except that 3.0 parts instead of 10% oleum were used andappropriate molar amounts of the phthalocyanine were used in place ofthe hexadeca(phenoxy) zinc phthalocyanine:

    ______________________________________                                        Phthalocyanine of Formula (3) used                                            Example                                                                              M       R.sup.1  a    x    b   Sulphonated Product                     ______________________________________                                        69     Ca      Ph       16   --   --  (SO.sub.3 Na).sub.16                    70     Mg      Ph       16   --   --  (SO.sub.3 Na).sub.16                    71     Zn      2-MePh   16   --   --  (SO.sub.3 Na).sub.16                    72     Zn      3-MePh   16   --   --  (SO.sub.3 Na).sub.16                    73     Zn      4-MePh   16   --   --  (SO.sub.3 Na).sub.16                    74     OHAl    4-MePh   16   --   --  (SO.sub.3 Na).sub.16                    75     Zn      Ph        4   Cl   12  (SO.sub.3 Na).sub.4                     ______________________________________                                         In all the above examples:                                                    Ph = phenyl                                                                   2MePh = 2methylphenyl                                                         3MePh = 3methylphenyl                                                         4MePh = 4methylphenyl                                                         4ClPh = 4chlorophenyl                                                         4OMePh = 4methoxyphenyl                                                       2Np = naphth2-yl                                                              1Np = naphth1-yl                                                              4NO.sub.2 Ph = 4nitrophenyl                                              

The ultraviolet, visible and infra red spectra were measured aschloroform and dichloromethane and H₂ O.

The singlet oxygen generating efficiencies SΔ of non-sulphonatedphthalocyanines were measured in benzene, or acetonitrile and ofsulphonated phthalocyanines in water.

The max values and S values are shown in Table 1.

                  TABLE 1                                                         ______________________________________                                        Example No.    λmax/nm (solvent)                                                                   SΔ %                                        ______________________________________                                         1             745 (CHCl.sub.3)                                                                           6                                                  2             726 (CHCl.sub.3)                                                                           43                                                 3             750 (CHCl.sub.3)                                                                           36                                                 4             726 (CHCl.sub.3)                                                                           22                                                 5             726 (CHCl.sub.3)                                                                           4                                                  6             717 (CHCl.sub.3)                                                                           5                                                  7             772 (CHCl.sub.3)                                                                           47                                                 8             730 (CHCl.sub.3)                                                                           111                                                9             739 (CHCl.sub.3)                                                                           30                                                10             740 (CHCl.sub.3)                                                                           46                                                11             720 (CHCl.sub.3)                                                                           110                                               12             723 (CHCl.sub.3)                                                                           73                                                13             745 (CHCl.sub.3)                                                                           46                                                14             738 (H.sub.2 O)                                                                            36                                                15             740 (H.sub.2 O)                                                                            46                                                16             701 (CH.sub.2 Cl.sub.2)                                                                    36                                                18             690 (CH.sub.2 Cl.sub.2)                                                                    55                                                37             694 (CH.sub.2 Cl.sub.2)                                                                    32                                                38             753 (CH.sub.2 Cl.sub.2)                                                                    51                                                39             782 (CH.sub.2 Cl.sub.2)                                                                    13                                                40             750 (CH.sub.2 Cl.sub.2)                                                                    52                                                41             736 (CH.sub.2 Cl.sub.2)                                                                    45                                                42             727 (CH.sub.2 Cl.sub.2)                                                                    38                                                43             725 (CH.sub.2 Cl.sub.2)                                                                    45                                                44             758 (CH.sub.2 Cl.sub.2)                                                                    24                                                45             742 (CH.sub.2 Cl.sub.2)                                                                    23                                                46             753 (CH.sub.2 Cl.sub.2)                                                                    34                                                47             721 (Acetone)                                                                              22                                                48             723 (CH.sub.2 Cl.sub.2)                                                                    24                                                49             722 (CH.sub.2 Cl.sub.2)                                                                    23                                                50             710 (CH.sub.2 Cl.sub.2)                                                                    8                                                 51             751 (CH.sub.2 Cl.sub.2)                                                                    15                                                52             725 (CHCl.sub.3)                                                                           23                                                53             752 (CHCl.sub.3)                                                                           19                                                54             736 (CH.sub.2 Cl.sub.2)                                                                    34                                                55             693 (CH.sub.2 Cl.sub.2)                                                                    29                                                56             705 (Acetone)                                                                              21                                                57             742 (CH.sub.2 Cl.sub.2)                                                                    28                                                58             702 (CH.sub.2 Cl.sub.2)                                                                    68                                                59             690 (CH.sub.2 Cl.sub.2)                                                                    46                                                60             678 (CH.sub.2 Cl.sub.2)                                                                    43                                                61             688 (DMF)    49                                                62             736 (CH.sub.2 Cl.sub.2)                                                                    34                                                63             693 (CH.sub.2 Cl.sub.2)                                                                    40                                                64             772 (CHCl.sub.3)                                                                           14                                                65             742 (CH.sub.2 Cl.sub.2)                                                                    13                                                66             714 (CH.sub.2 Cl.sub.2)                                                                    21                                                67             741 (CH.sub.2 Cl.sub.2)                                                                    13                                                68             717 (H.sub.2 O)                                                                            10                                                69             742 (H.sub.2 O)                                                                            8                                                 70             732 (H.sub.2 O)                                                                            17                                                71             726 (H.sub.2 O)                                                                            67                                                72             724 (H.sub.2 O)                                                                            52                                                73             705 (H.sub.2 O)                                                                            39                                                74             736 (H.sub.2 O)                                                                            62                                                75             686 (H.sub.2 O)                                                                            6                                                 ______________________________________                                    

The stain removal aspects of the invention are illustrated by thefollowing examples.

In Examples 76-91 the following procedure was used.

Cotton cloth was cut into 7.5 cm×10 cm pieces and the pieces werestained by allowing them to soak for 2 hours in a tea solution preparedfrom 2 tea bags and 1 liter of water. The cloth pieces were dried in atumbler dryer and stored in the dark until needed.

The wash tests were carried out in a stirred metal bath at 40° C. using(i) 9 g of a commercially available biological washing liquid (Ariel)per liter of water or (ii) 3 g of a commercially available non-aqueousbiological washing liquid (from Marks and Spencer PLC) per liter ofwater. 0.003 g of a compound of Formula (2) or 0.003 g of a compound ofFormula (3) was added per liter of water to provide a wash solution.Three cloth pieces were added to each wash solution and these werestirred at 40° C. for 10 minutes. The cloth pieces were rinsed well withwater and dried in direct sunlight. The effect of each compound ofFormulae (2) or (3) was assessed by measuring the reflectance of eachdried cloth piece and comparing it with an unwashed cloth piece.Reflectance measurements were obtained using a Gardener Colorgardreflectometer. The results were calculated using ##EQU1## where A=%improvement of washed versus unwashed cloth

R=% reflectance of washed cloth piece

U=% reflectance of unwashed cloth piece.

The results are summarised in Table 2 below.

                  TABLE 2                                                         ______________________________________                                        Example Compound added to wash solution                                                                        A                                            ______________________________________                                        (a) Biological washing liquid                                                 76      None                          0.8                                     77      ZnPc(2-naphthyl-O).sub.16                                                                        (e.g. 8)  25.7                                     78      OHA1PC(Ph-O).sub.16 (SO.sub.3 H).sub.16                                                          (e.g. 14) 14.1                                     79      OHA1Pc(2-naphthyl-O).sub.16 (SO.sub.3 H).sub.30                                                  (e.g. 13) 16.2                                     80      H.sub.2 Pc(2-naphthyl-O).sub.16 (SO.sub.3 H).sub.30                                              (e.g. 15) 21.9                                     81      ZnPc(Ph-O).sub.16 (SO.sub.3 H).sub.16                                                            (e.g. 11) 31.4                                     82      ZnPc(2-naphthyl-O).sub.16 (SO.sub.3 H).sub.30                                                    (e.g. 12) 31.5                                     83      H.sub.2 Pc(Ph-O).sub.16 (SO.sub.3 H).sub.20                                                      (e.g. 9 & 10)                                                                           27.5                                     (b) Non-aqueous biological washing liquid                                     84      None                          4.9                                     85      ZnPc(2-naphthyl-O).sub.16                                                                        (e.g. 8)  29.9                                     86      OHA1Pc(Ph-O).sub.16 (SO.sub.3 H).sub.16                                                          (e.g. 14) 17.6                                     87      OHA1Pc(2-naphthyl-O).sub.16 (SO.sub.3 H).sub.30                                                  (e.g. 13) 18.1                                     88      H.sub.2 Pc(2-naphthyl-O).sub.16 (SO.sub.3 H).sub.30                                              (e.g. 15) 25.8                                     89      ZnPc(Ph-O).sub.16 (SO.sub.3 H).sub.16                                                            (e.g. 11) 25.2                                     90      ZnPc(2-naphthyl-O).sub.16 (SO.sub.3 H).sub.30                                                    (e.g. 12) 26.3                                     91      H.sub.2 Pc(Ph-O).sub.16 (SO.sub.3 H).sub.20                                                      (e.g. 9 & 10)                                                                           29.6                                     ______________________________________                                    

We claim:
 1. A compound of the Formula ( 3):

    M.sub.k Pc(O-R.sup.1).sub.a X.sub.b                        Formula ( 3)

wherein: M_(k) Pc is as defined in Formula (1): ##STR5## wherein: M isselected from the group consisting of Zn, ClAl, OHAl, ClRh, OHRh, Clln,Brln OHln, ClGa, OHGa, Pt, Pd, Li, Na, K, Ca, Ba, Mg, ClSc and OHSc; kis the inverse of 1/2 of the valency of M_(k) ; R¹ is selected from thegroup consisting of phenyl, naphthyl, pyridyl, thiophenyl, furanyl,quinolinyl, thiazolyl, benzothiazolyl, pyrimidyl, each of whichindependently is unsubstituted or substituted by a substituent selectedfrom the group consisting of C₁₋₂₀ -alkyl, C₁₋₂₀ -alkoxy, C₂₋₂₀-alkenyl, C₁₋₂₀ -alkylthiol, C₁₋₂₀ -alkoxycarbonyl, hydroxy C₁₋₄-alkoxy, phenyl, benzyl, phenylthio, fluoro, chloro, bromo, --CN, --NO₂,--CF₃, --COR², --COOR², --CONR² R³, --SO₂ R², --SO₂ NR² R³, --NR² R³ and--OR² in which R² and R³ are each independently H, C₁₋₄ -alkyl orphenyl; X is halogen or H; a is an integer selected from 4, 8, 12 and16; b is an integer from 0 to 15; a+b is equal to 16; provided that whenM is ClGa or Clln, X is halogen and a is 4, 8, or 12; and provided thatwhen M is AlCl, a is 16;except for the compounds: GaCl Pc(Ph--O)₈ Cl₈,ZnPc(Ph--O)₄ H₁₂, ZnPc(4-NO₂ Ph--O)₄ H₁₂, ZnPc(4-NH₂ Ph--O)₄ H₁₂,ZnPc(HOPh--O)₄ H₁₂, MgPc(2-Br-4-Me (CH₂)₄ Ph--O)₄ H₁₂, ZnPc(4-Me(CH₂)₆Ph--O)₄ H₁₂ and Li₂ Pc(2-naphthyl-O)₈ H₈.
 2. A compound of the Formula(3):

    M.sub.k Pc(O--R.sup.1).sub.a X.sub.b                       Formula ( 3)

wherein: M_(k) Pc is as defined in Formula (1): ##STR6## wherein: M isselected from the group consisting of Zn, ClAl, OHAl, ClRh, OHRh, Clln,Brln OHln, ClGa, OHGa, Pt, Pd, Li, Na, K, Ca, Ba, Mg, ClSc and OHSc; kis the inverse of 1/2 of the valency of M_(k) ; R¹ is selected from thegroup consisting of phenyl, naphthyl, pyridyl, thiophenyl, furanyl,quinolinyl, thiazolyl, benzothiazolyl, pyrimidyl, each of whichindependently is unsubstituted or substituted by a substituent selectedfrom the group consisting of C₁₋₂₀ -alkyl, C₁₋₂₀ -alkoxy, C₂₋₂₀-alkenyl, C₁₋₂₀ -alkylthiol, C₁₋₂₀ -alkoxycarbonyl, hydroxy C₁₋₄-alkoxy, phenyl, benzyl, phenylthio, fluoro, chloro, bromo, --CN, --NO₂,--CF₃, --COR², --COOR² ₁ --CONR² R³, --SO₂ R², --SO₂ NR² R³ ₁, --NR² R³and --OR² in which R² and R³ are each independently H, C₁₋₄ -alkyl orphenyl; X is halogen or H; a is an integer selected from 8, 12 and 16; bis an integer from 0 to 15; a+b is equal to 16;except for the compounds:ClAlPc(2-naphthyl-O)₈ H₈, Li₂ pc(2-naphthyl-O)₈ H₈, ClGaPc(Ph--O)₈ H₈,ClGaPc(Ph--O)₈ Cl₈, ClAlPc(2-naphthyl-O)₈ Cl₈ ClGaPc(Ph--O)₁₆CllnPc(2-naphthyl-)₁₆.
 3. A compound of the Formula (3):

    M.sub.k Pc(O--R.sup.1).sub.a X.sub.b                       Formula ( 3)

wherein: M_(k) Pc is as defined in Formula (1): ##STR7## wherein: M isselected from the group consisting of Zn, ClAl, OHAl, ClRh, OHRh, Clln,Brln, OHln, OHGa, Pt, Pd, Li, Na, K, Ca, Ba, Mg, ClSc and OHSc; k is theinverse of 1/2 of the valency of M_(k) ; R¹ is selected from the groupconsisting of phenyl, naphthyl, pyridyl, thiophenyl, furanyl,quinolinyl, thiazolyl, benzothiazolyl, pyrimidyl, each of whichindependently is unsubstituted or substituted by a substituent selectedfrom the group consisting of C₁₋₂₀ -alkyl, C₁₋₂₀ -alkoxy, C₂₋₂₀-alkenyl, C₁₋₂₀ -alkylthiol, C₁₋₂₀ -alkoxycarbonyl, hydroxy C₁₋₄-alkoxy, phenyl, benzyl, phenylthio, fluoro, chloro, bromo, --CN, --NO₂,--CF₃, --COR², --COOR², --CONR² R³, --SO₂ R², --SO₂ NR² R³, --NR² R³ and--OR² in which R² and R³ are each independently H, C₁₋₄ -alkyl orphenyl; X is halogen or H; a is an integer selected from 8, 12 and 16; bis an integer from 0 to 15; a+b is equal to 16; provided that when M isClln, X is halogen; provided that when M is AlCl, a is 16; and providedthat when M is Li, a is 12 or
 16. 4. A compound according to claim 1wherein a is 8, 12 or
 16. 5. A compound according to claim 1 wherein Mis selected from Zn, ClAl and OHAl.
 6. A compound according to claim 1wherein R¹ is phenyl or naphthyl each of which is unsubstituted orsubstituted by a substituent selected from the group consisting of C₁₋₂₀-alkyl, C₁₋₂₀ -alkoxy, C₁₋₂₀ -alkenyl, C₁₋₂₀ -alkylthiol, C₁₋₂₀-alkoxycarbonyl, hydroxy C₁₋₄ -alkoxy, phenyl, benzyl, phenylthio,fluoro, chloro, bromo, --CN, --NO₂, --CF₃, --COR², --COOR² ₁, --CONR²R³, --SO₂ R₂, --SO₂ NR² R³, --NR² R³ and --OR² in which R² and R³ areeach independently H, C₁₋₄ -alkyl or phenyl.
 7. A compound according toclaim 1 wherein R¹ is phenyl or naphthyl each of which is unsubstitutedor substituted by a substituent selected from the group consisting ofC₁₋₂₀ -alkyl, C₁₋₂₀ -alkoxy, hydroxy, chloro and --NO₂.
 8. A compoundaccording to claim 1 wherein:M is selected from the group consisting ofZn, ClAl and OHAl; a is 16; and R¹ is phenyl or 2-naphthyl.
 9. Acompound according to claim 1 wherein:M is Zn or Mg; a is 16; and R¹ isselected from phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl or2-naphthyl.
 10. A compound according to claim 1 wherein:M is selectedfrom the group consisting of Zn, Mg and OHAl; a is 4; R¹ is selectedfrom phenyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl and2-naphthyl; X is halogen; and b is
 12. 11. A compound according to claim1 wherein:M is Zn or Mg; a is 8; and R¹ is selected from phenyl,2-methylphenyl, 3-methylphenyl, 4-methylphenyl and 2-naphthyl.
 12. Acompound according to claim 1 wherein:M is selected from the groupconsisting of Zn, Mg and OHAl; a is 12; and R¹ is selected from phenyl,2-methylphenyl, 3-methylphenyl, 4-methylphenyl and 2-naphthyl.